Effect of the forced-suction airflow volume ratio on the dust suppression of swirling air curtain in fully mechanized excavation face

In order to solve the problem of dust pollution in fully mechanized excavation face of coal mine, this article took the fully mechanized excavation face of 3110 haulage gateway in Tangkou Coal Mine as the research object, numerically simulated the structure evolution and dust suppression of swirling air curtain when the forced-suction airflow volume ratio "r" was 0.5, 0.8, 1.2 and 1.5. The results show that with the decrease of r, the main factor that controls the airflow structure transforms from inertia to negative pressure, the axial migration distance of the air curtain with radial swirling state and the low- speed turbulence zone in front of it are reduced accordingly. When r drops to 0.8 and 0.5, the axial dust control airflow field can be formed in the driving area, and the range of dust pollution is reduced. Considering the actual situations in fully mechanized excavation face, r was finally determined to be 0.8. After on-site application, a relatively complete axial dust-blocking flow field was formed on the front section of the tunneling driver. The airflow velocity range was reduced to the range of 0.38 m/s to 1.19 m/s, the dust mass concentration at the tunneling driver was dropped to 63.0 mg/m³.